Coating plants that are operated under vacuum or near-vacuum conditions make use of charging locks, for example, for the transfer of the substrates into and out of the reaction chamber or the coating chamber. For this purpose there are known rectangular vacuum locks with rectangular lock shutters or lock disks that have a length of 1000 to 1500 mm and a width of about 50 mm. With a view to assuring tight and, especially, gastight closure of the lock aperture, it is the normal practice to secure the lock shutter or the lock disk with a latch that will maintain the shutter or the lock disk in the closed position. Due to the size of the lock aperture, the pressure differences between atmospheric conditions on the one hand and vacuum conditions on the other will give rise to substantial forces that have to be absorbed by the device for the closure of the lock aperture while yet maintaining the gastight closure of the lock.
At the same time, however, the transfer of the substrates through the lock affects the cycle times for the coating in the coating plants. It is therefore necessary for the lock apertures of the lock to be opened and closed quickly in order to save time for the opening and closing steps, because the evacuation or venting of the lock and/or the coating chamber cannot be started unless and until the appropriate apertures are closed in a tight and especially a gastight manner.